Celtic manager Neil Lennon has told his players to "hold their heads high" as he took the blame for the "bitter disappointment" of defeat to Rangers.
The meek 2-0 home loss in Saturday's derby left Celtic - chasing a record 10th consecutive title - four points behind Rangers with a game in hand.
Lennon is seeking a positive reaction in the Europa League Group H opener at home to AC Milan on Thursday.
"These players are amazing and have done amazing things," he said.
"I'm confident they'll continue to do amazing things for the club. We weren't very good, particularly in the second half, on Saturday and that's on me. I have to take responsibility for the performance, not the players.
"There is a long way to go. We are not happy with the result but there is plenty of time to improve and bounce back."
While Lennon feels there has been an "over-reaction" to the loss - Celtic's first successive Old Firm defeats in 11 years - he admits his team have yet to hit top form this season.
"The performances haven't been up to the level we're capable of and I'm hoping that's turned around as we go along," the Celtic boss added. "We can be more purposed and penetrating.
"All is not lost on one result. We're all disappointed but we can't dwell on that. We're not smoothing things over as if everything is okay.
"You have to accept the criticism and we're looking to react positively. We're working really hard now to get back to the quick, penetrating football we're capable of."
Lennon says the visit of Serie A leaders AC Milan is the biggest game he's faced since returning to manage Celtic.
The Italian giants have won their opening four league games, with 39-year-old striker Zlatan Ibrahimovic scoring a match-winning double in the weekend derby against Inter.
"He's right up there for me among the greatest players of all time with what he's achieved in different leagues and clubs and with his country," said Lennon.
"He's still a world-class player. He's a great role model, a one-off, very special."